Recursive formalism with a minimal dynamic parameterization for the identification and simulation of multibody systems. Application to the human body

This paper presents a multibody formalism using a minimal set of dynamical parameters, based on the barycentric approach. Using relative joint coordinates, we show that it is possible to generate recursively the inverse and direct dynamics in terms of this minimal set, rather than using the classical ones (mass, centre of mass and inertia matrix). More than providing a very compact scheme in terms of flops, the proposed formalism, in which the independent dynamical parameters appear linearly, is a precious tool for identification purpose; indeed, the recursive nature of the formalism and its symbolic implementation allows us to deal with very large models, such as the human body for instance. The approach is then applied to the identification of some of the human body's dynamical parameters, on the basis of a trajectory issuing from a volleyball typical movement.